The Infinaut is a minor hero featured in Marvel comics, debuting in Ultimates vol 3 #9, "A Voice From The Dark", which was published in 2016. He is an explorer from a higher dimension who was first thought to be an invader, and would later join a redeemed Galactus in saving the personification of Eternity from the First Firmament. Externally, the Infinaut resembles a human with orange hair, but bears green skin, and due to his extradimensional nature, is gargantuan in size, large enough to destroy planets by simply landing on them. Additionally, he is clad in a technologically advanced space suit equipped with a translator and jetpack, which may imply that he is unable to survive outside his home dimension without the right protection. While shown to rely on his suit and weapons, the Infinaut is considered a cosmic being and treated as an equal to Galactus and the rest of the Eternity Watch, but it is unclear if his cosmic power is the result of his suit or just his biology.
While the Infinaut was last seen in comics in 2017, he was added to Marvel Snap as a high-value card in 2022.
Biography
Early manifestations
Little is known about the Infinaut, other than he comes from a higher dimension of macro-space, and is thus a supergiant. However, it is also known that he is a scientist who sought to explore other dimensions, such as Earth-616. With his power, the Infinaut attempted to access Earth's dimension in the 1990s, but his massive size would have made his landing incredibly destructive, a fact the being was seemingly not aware of. Additionally, his manifestation attempt created localized space-time ripples that notified Dr. Adam Brashear, better known as Blue Marvel, to the Infinaut's incoming arrival, finding that the ripples gave a 10-hour warning. Assuming the Infinaut to be an invader, Brashear used an antimatter rig to repel the Infinaut, keeping him out of the universe.
In 1998, the Infinaut attempted to reach Earth again, starting to manifest in Machu Piccu, Peru. However, Brashear and his son Kevin were ready, and once again cut off the Infinaut's dimensional transport. Five more times in the following decades, the Infinaut tried to reach Earth, but each time, he was stopped by Brashear. On his eight manifestation, the Infinaut began to manifest over Quezon City in the Philippines, but was repelled by the Triumph Division, a superhero team from the country.
9th Manifestation
Years later, Inhuman precog Ulysses Cain foresaw the ninth manifestation of the Infinaut, eight days before it happened. However, Ulysses also revealed that the Infinaut was not an invader, but rather, a scientist trying to make contact with Earth. With that, Brashear and a response team of the Ultimates, accompanied by Captain Marvel and Black Panther, prepared a way to finally get the Infinaut safely on the planet. One of the Ultimates members, Giant-Man, assembled a Pym Particle accelerator to do so, and on the day of the manifestation, the heroes gathered in the detected site of the Infinaut's landfall. This time, the Infinaut was able to fully manifest his body through a portal in the sky, which was the first time Brashear was able to see his real appearance, and Giant-Man grew as big as he could, taking hold of the Infinaut's hand before the Infinaut's full mass could come through, serving as an anchor to guide the Infinaut into Earth's dimension, Black Panther working to shrink them both down as fast as possible, stabilizing the Infinaut's height down to 1.98 meters tall, allowing the Infinaut to land at last.
On the ground, the Infinaut used his suit's translator to greet the heroes, shaking hands with Captain Marvel and expressing his happiness at being able to finally meet the people of Earth. While it is unknown how long the Infinaut remained on Earth, Brashear mentioned that the Infinaut exchanged scientific knowledge with humans.
Eternity War
Sometime later, across the multiverse, the personification of Eternity was captured by the First Firmament, prompting the world-eater Galactus, now redeemed as the Life Bringer, to assemble the Eternity Watch, an alliance of other powerful cosmic entities he considered equals, in order to rescue Eternity. Despite being a scientist, the Infinaut was asked to join, and accepted, forming the group alongside Galactus, Ego-Prime, and Psi-Hawk. Armed with a giant alien raygun, the Infinaut accompanied the Eternity Watch in battling the First Firmament and its servants, the Aspirants and Logos, aided by the Queen of the Nevers, the personification of possibilities, and a Tiger God-ascended Black Panther, the Infinaut blasting apart several Aspirants and making technical analyses of the events. Ultimately, Eternity Watch succeeded in destroying the Aspirants and Logos, freeing Eternity itself. After the repowered Eternity imprisoned the First Firmament, the Infinaut presumably returned to his position as an interdimensional scientist.